NHRA 101: Pro Stock Body
With no power adders allowed and a strict displacement limit of 500 cubic inches, a ...
With no power adders allowed and a strict displacement limit of 500 cubic inches, a modern Pro Stock car has to be as efficient as possible to cover the quarter mile in just over 6.5 seconds at 210+ MPH. This means teams and chassis builders alike do everything they can to make the car slippery, and NHRA’s own Bruno Massell lets us in on a couple of those tricks in this NHRA 101 segment.
Legendary chassis builder Don Ness, who passed away last spring, designed the current NHRA Pro Stock Camaro body to punch through the air with the least resistance possible and in doing so, created the body with the lowest drag coefficient of any doorslammer design. When your engine is reliant on Mother Nature to cram the air into the intake, every little bit helps so building a car with a drag coefficient of just 0.20.
While the cars would certainly be more stable and safer with more rear downforce, that would create more drag and slow the cars down. Instead, they run a small rear spoiler that creates just 150 pounds of downforce at 200 MPH, which is practically nothing compared to the 5,000 pounds created by the wing on a top fuel car.
Of course, that comes back to the difference in combination and horsepower, where a fuel car has 11,000 horsepower, a strong running Pro Stock car typically making just 1,500 or so.
While the cars do have to meet minimum weight to be legal for the class, the tuners would rather be able to pick and choose where they place weight to make the most efficient use possible of every pound. That means the body needs to be as lightweight as possible, and thanks to carbon fiber, these bodies come out of the mold weighing just 35-40 pounds. Of course, by the time they’re installed with bracing, fasteners, and paint they weigh a few more pounds, but they’re still light enough to give the chassis guys a lot of leeway in where they place their weight.